Bosch Standard Battery Charger- 4A- the smart systemThe 4A Charger is the perfect charger with many advantages: It charges quickly, is easy to use and is visually appealing. The compact and lightweight charger is ideal for when on the go and quickly supplies the PowerTube 750 with the necessary energy: It takes six hours to fully charge the battery, and just over two hours for a 50% charge. Compatible with components of the smart system Charging time for PowerTube 750: 50% in approx. 2. 3 hours, 100%